有调查显示,超过八成的家庭使用大管(125克以上)牙膏。人们普遍认为,大管牙膏在价钱上更划算,而且能用很长时间。其实,用小管牙膏反而更好,因为牙膏使用时间越久,暴露在空气中的机会就越多,与牙刷的接触频率就越高,接触细菌的机会也就大 A survey shows that more than Bacheng family use a large tube (125 grams) toothpaste. It is generally believed that the big tube toothpaste is more cost-effective, and can be used for a long time. In fact, the use of small tube toothpaste instead better, because the longer the toothpaste use, the more the chance of exposure to the air, the higher the frequency of contact with the toothbrush, the chance of exposure to bacteria is large